Abstract: Polyurethane-fluorinated polysiloxane (PU-^FPDMS) with high-strength, high-bonding and low surface energy is synthesized as the matrix, and the PU-^FPDMS/ MCs/Ag marine anti-fouling coating on the surface of imitation crab shells is constructed by assembling butenolide@1,1-stilbene-modified hydrolyzed polyglycidyl methacrylate/graphene oxide microcapsules (Bu@PGMA_m/GO MCs) with compact multi-shell structure and Ag nanoparticles (AgNPs) step by step on the PU-^FPDMS matrix. The PU-^FPDMS/ MCs/Ag bionic anti-fouling coatings achieve long-term and stable anti-fouling effect under the combination of robust low-surface-energy PU-^FPDMS matrix, steady-state sustained release of butenolide encapsulated by the compact multi-shell, bionic surface formed by the microcapsules and AgNPs, and the release of Ag⁺. The shear strength, tensile strength, and elongation at break of the PU-^FPDMS/ MCs/Ag are 3.53 MPa, 6.7 MPa, and 192.83 %, respectively. Its static contact angle and sliding angle are 161.8° and 3.6°, respectively. The antibacterial rate of PU-^FPDMS/MCs/Ag against Escherichia coli, Staphylococcus aureus, and Candida albicans can reach 100 %. Compared with glass blank, PU, PU-^FPDMS, PU-^FPDMS/Ag, and PU-^FPDMS/MCs, both the adhesion number and coverage percentage of chlorella adhere to PU-^FPDMS/MCs/Ag are the minimum values, which are 600 cell mm^-2 and 1.53 %, respectively. After 6 months of marine field test, the primer blank, PU, PU-^FPDMS all show different degrees of attachment by shellfish, spirorbis, algae and other biofouling, while the PU-^FPDMS/MCs/Ag coating is still not covered with biofouling, while the PU-^FPDMS/MCs/Ag coatings still exhibit little attachment of marine fouling. The PU-^FPDMS/ MCs/Ag bionic anti-fouling coatings are expected to be widely used in the fields of anti-fouling, anti-icing, anti-fogging, drag reduction, self-cleaning, and antibacterial.

Key words: Marine anti-biofouling, Bionic, Coating, Long-term and stable anti-fouling